I don't think the complexity of the voting system had a huge impact on why Slashdot waned in popularity. That said, I can see a simpler system where it asks you

I don't think the complexity of the voting system had a huge impact on why Slashdot waned in popularity. That said, I can see a simpler system where it asks you why you upvoted or downvoted and provides multiple pre-set "reasons" for you to click on. The problem is using those responses to find something you want to read. Tastes and interests change over time. You might be obsessed with electric cars for a month, then want to read anything but electric cars the next month. That's the problem with using past data in this case; it's not a great predictor of the future. Social sharing of information from actual people is better and we already have lots of that. So what's missing? Why do we feel news "aggregators" like Twitter and facebook aren't good enough?